Silicon waveguides have large birefringence, which makes the waveguide highly polarization dependent. As a result, silicon photonic devices, such as sub-micron silicon photonics devices are strongly polarization dependent.
In addition, the silicon in silicon photonic devices has a large thermo-optical coefficient. As a result, silicon photonic devices, such as photonics filters, experience a large wavelength shift due to a variation of the ambient temperature. In order to stabilize a waveguide, a constant temperature environment is required. However, temperature control is achieved through additional power consumption.
There is a great interest in achieving polarization insensitive and temperature insensitive phase delay in a silicon photonic device including one or more waveguides.